Andreas J. Smout

Chicago classification criteria of esophageal motility disorders defined in high resolution esophageal pressure topography.

Background  The Chicago Classification of esophageal motility was developed to facilitate the interpretation of clinical high resolution esophageal pressure topography (EPT) studies, concurrent with the widespread adoption of this technology into clinical practice. The Chicago Classification has been an evolutionary process, molded first by published evidence pertinent to the clinical interpretation of high resolution manometry (HRM) studies and secondarily by group experience when suitable evidence is lacking.

Esophageal acid exposure decreases intraluminal baseline impedance levels.

OBJECTIVES:Intraluminal baseline impedance levels are determined by the conductivity of the esophageal wall and can be decreased in gastroesophageal reflux disease (GERD) patients. The aim of this study was to investigate the baseline impedance in GERD patients, on and off proton pump inhibitor (PPI), and in healthy controls.METHODS:Ambulatory 24-h pH–impedance monitoring was performed in (i) 24 GERD patients with and 24 without pathological esophageal acid exposure as well as in 10 healthy controls and in (ii) 20 patients with refractory GERD symptoms despite PPI, once on PPI and once off PPI. Baseline impedance levels in the most distal and the most proximal impedance channels were assessed.RESULTS:Median (interquartile range) distal baseline impedance in patients with physiological (2,090 (1,537–2,547) Ω) and pathological (781 (612–1,137) Ω) acid exposure was lower than in controls (2,827 (2,127–3,270) Ω, P<0.05 and P<0.001). A negative correlation between 24-h acid exposure time and baseline impedance was observed (r=−0.7, P<0.001). In patients measured off and on PPI, median distal baseline impedance off PPI was significantly lower than on PPI (886 (716–1,354) vs. 1,372 (961–1,955) Ω, P<0.05) and distal baseline impedance in these groups was significantly lower than in healthy controls (P<0.05 and P<0.001). Proximal baseline impedance did not differ significantly between the patients off PPI and on PPI (1,793 (1,384–2,489) vs. 1,893 (1,610–2,561) Ω); however, baseline impedance values in both measurements were significantly lower than in healthy controls (3,648 (2,815–3,932) Ω, both P<0.001).CONCLUSIONS:These findings suggest that baseline impedance is related to esophageal acid exposure and could be a marker of reflux-induced changes to the esophageal mucosa.

Rapidly increasing incidence of eosinophilic esophagitis in a large cohort

Background  Recent literature has shown increasing incidence and prevalence rates of eosinophilic esophagitis (EoE). However, data are mainly based on small studies and come from centers dedicated to EoE. Aim of this study was to estimate the incidence rates of EoE by using a large database.

PPI therapy is equally effective in well-defined non-erosive reflux disease and in reflux esophagitis: a meta-analysis.

Background  Symptomatic response to proton pump inhibitor (PPI) therapy in patients with non‐erosive reflux disease (NERD) is often reported as lower than in patients with erosive reflux disease (ERD). However, the definition of NERD differs across clinical trials. This meta‐analysis aims to estimate the rate of symptom relief in response to PPI in NERD patients.

Characterization of idiopathic esophagogastric junction outflow obstruction

Esophagogastric junction (EGJ) outflow obstruction is a manometric diagnosis, characterized by an elevated relaxation pressure (IRP4) of the lower esophageal sphincter (LES) and intact or weak peristalsis. The etiology and preferred treatment remain unknown. We describe a large patient cohort in detail, for a better understanding of this rare disorder.

Normative values in esophageal high-resolution manometry.

Esophageal high‐resolution manometry (HRM) has rapidly gained much popularity worldwide. The Chicago Classification for esophageal motility disorders is based on a set of normative values for key metrics that was obtained using one of the commercially available HRM systems. Thus, it is of great importance to evaluate whether these normative values can be used for other HRM systems as well.

Prevalence of esophageal motility abnormalities increases with longer disease duration in adult patients with eosinophilic esophagitis

During the natural course of eosinophilic esophagitis (EoE), the risk for esophageal stricture formation increases. It remains unknown whether motility abnormalities in EoE also develop over time. We aimed to determine the relationship between disease duration, clinical characteristics, and manometric pattern of EoE patients.

Electrical tissue impedance spectroscopy: a novel device to measure esophageal mucosal integrity changes during endoscopy

Patients with gastroesophageal reflux disease (GERD) have impaired esophageal mucosal integrity. Measurement of the mucosal integrity is complex and time‐consuming. Electrical tissue impedance spectroscopy (ETIS) is a device that measures impedance of tissue in vivo during endoscopy. In this study, we aimed to validate ETIS as a measure of esophageal mucosal integrity.

Accuracy of hiatal hernia detection with esophageal high-resolution manometry.

The diagnosis of a sliding hiatal hernia is classically made with endoscopy or barium esophagogram. Spatial separation of the lower esophageal sphincter (LES) and diaphragm, the hallmark of hiatal hernia, can also be observed on high‐resolution manometry (HRM), but the diagnostic accuracy of this finding has not yet been investigated. To determine the diagnostic value of HRM in the detection of hiatal hernia.

Patients with refractory reflux symptoms often do not have GERD.

In patients with typical reflux symptoms that persist despite proton pump inhibitors (PPIs) it is sometimes overlooked that treatment fails due to the presence of other disorders than gastroesophageal reflux disease (GERD). The aim of this study was to determine the underlying cause of reflux symptoms not responding to PPI therapy in tertiary referral patients.